Converting JSON Array to object using JQ

Question

I would like to ask for help. How can I transfer array to one list. My input is

[
  {
    "PartNumber": "5SD30104GN114",
    "ClassificationNo": "500001",
    "StringValue": "L0035WSGE",
    "Field": "95001"
  },
  {
    "PartNumber": "5SD30104GN114",
    "ClassificationNo": "500001",
    "StringValue": "",
    "Field": "95002"
  }
]

And I like to expect this

[
  {
    "PartNumber": "5SD30104GN114",
    "ClassificationNo": "500001",
    "95001": "L0035WSGE",
    "95002": "",
  }
]

How Can I do ? I tried use

| .[] | [.PartNumber, .ClassificationNo, .StringValue, .Field]

But generate again arrays

[
  "5SD30104GN114",
  "500001",
  "L0035WSGE",
  "95001"
]
[
  "5SD30104GN114",
  "500001",
  "",
  "95002"
]

knittl · Accepted Answer · 2022-10-07 16:29:32Z

1

Here's a solution using reduce:

group_by({PartNumber,ClassificationNo})
| map(reduce .[] as $item ({}; .+($item|{PartNumber, ClassificationNo, (.Field):.StringValue})))

Probably not the most efficient one (part number and classification number are always overwritten), but it gets the job done while being somewhat readable.

Output:

[
  {
    "PartNumber": "5SD30104GN114",
    "ClassificationNo": "500001",
    "95001": "L0035WSGE",
    "95002": ""
  }
]

With a function:

def reducer($item):
  $item|{PartNumber, ClassificationNo, (.Field):.StringValue};

group_by({PartNumber,ClassificationNo})
| map(reduce .[] as $item ({}; .+reducer($item)))

answered Oct 7, 2022 at 16:29

knittl

269k59 gold badges339 silver badges405 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

pmf · Accepted Answer · 2022-10-07 11:14:03Z

You can use group_by to make clusters of matching IDs (I assumed .PartNumber together with .ClassificationNo to make a unique ID), then within each cluster, take the ID fields from the first item (all have the same ID fields), and add to it the values of all items by converting them to a key-value structure that can be used with from_entries to turn it into an object:

group_by([.PartNumber, .ClassificationNo]) | map(
  (first | {PartNumber, ClassificationNo}) +
  (map({key: .Field, value: .StringValue}) | from_entries)
)

Demo

Instead of from_entries, you can also use INDEX to create an object with the right fields, but then subsequently the values need to be trimmed down to only contain the right values:

group_by([.PartNumber, .ClassificationNo]) | map(
  (first | {PartNumber, ClassificationNo}) +
  (INDEX(.Field) | .[] |= .StringValue)
)

Demo

[
  {
    "PartNumber": "5SD30104GN114",
    "ClassificationNo": "500001",
    "95001": "L0035WSGE",
    "95002": ""
  }
]

Collectives™ on Stack Overflow

Converting JSON Array to object using JQ

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related